Excluding posts that are in one specific category only

Hi everyone

I’m going crazy over this, as it should be a dead simple thing, but I can’t figure out how to solve it and I haven’t found any notes on it either. What I’d like to do is this:

On an Author page (is_author) I’d like to exclude posts that are in my “News” category (cat_ID=7) only. Excluding the posts is easily done, but I’d like to keep posts that have other categories assigned to them as well, e.g. hide posts that are ONLY in the “News” category.

Is there a good way to go about this?

Thanks in advance!

/ Carl-Johan